In railway track aligning operations the problem of spring-back of the rail producing a tendency to move the track, after correction, out of its corrected position has long been observed. Proposals have been made to overcome this phenomenon by overcorrecting the track during aligning, that is to say, moving the track from an incorrect position through and beyond its correct position to a degree which will compensate for the rail spring-back, such that after spring-back the rail, and consequently the track, will adopt a correct position.
While these methods have produced a satisfactory solution to the problem of rail spring-back in a number of applications certain ballast conditions have caused the application of these methods to be somewhat difficult and time consuming, and the results less than satisfactory.